Project Info

SR 99 - W Fork Hylebos Creek - Fish Passage - Completed October 2015

Contractor crews working for WSDOT installed a larger culvert that carries West Fork Hylebos Creek under SR 99 near Federal Way.

Crews also realigned and regraded the creek to slow the water flow.

The new 10-by-20 foot wide culvert and rebuilt stream allows Chinook, coho and chum salmon to more easily pass under SR 99.
The previous culvert was installed in 1925 and often became clogged with debris and branches, creating impassable barriers for fish.


How you benefit

Protects environment
Replacing the culvert and rebuilding the stream helps protect and preserve salmon habitat:

  • a larger culvert allows fish to more easily pass under SR 99
  • a slower-moving stream creates more areas for spawning fish to rest
  • fish can now access several additional miles of the stream and eventually make their way into the West Hylebos Wetland Park
  • Non-native bushes and trees were removed and native bushes and trees planted
  • Improved habitat for other animals including frogs, birds and small mammals


Partnerships & cooperation
WSDOT worked with the City of Federal Way to coordinate this work.


2005 Gas Tax (TPA):  $2,651,000
Total: $2,651,000


Contact us
WSDOT communications
15700 Dayton Avenue North
Shoreline, WA 98133

A small map showing the location of the west fork of Hylebos Creek under SR 99 near Federal Way. Contractor crewreplaced the existing box culvert under SR 99 with a new larger culvert that does not block fish in the creek.
View larger map

This photo shows West Fork Hylebos Creek flowing under SR 99 in the new, larger culvert.
View more photos of this project on our Flickr page.